Apparatus for preparing pulverized fuel for combustion



Sept. 22, 1931. H. T. DYER 1,823,932

APPARATUS FOR PREPARING PULVERIZED FUEL FOR COMBUSTION Filed April 14; 1928 2 Sheets-Sheet 1 Fig l BYW %W ATTORNEYS.

INVENTOR. 44% a M.

H. T. DYER 1,823,932

APPARATUS FOR PREPARING PULVERIZED FUEL FOR COKBUSTION Sept. 22, 1931.

. 1928 2 Sheets-Sheet 2 Filed April 14 INVENTOR.

BY W: W

' Q/A TTDORNEYS.

Patented Sept. 22, 1931 UNITED-STATES PATENT OFFICE I HORACE r. DYLER, or GRuENwIoH, oouuuorrcur, ASSIGNOR r0 PEABODY ENGINEER- ms coaronarron, on NEW YORK, N. Y., A ooarouarron OF NEW YORK APPARATUS FOR PREPARING PULVERIZED FUEL FOR C(TMBUSTION Application filed April 14,

My invention relates to a system in which finely divided particles of any material'are conveyed through a pipe or conduit in sus- M pension in air and where it is desired to obltain at. any point in such pipe or conduit a homogeneous or balanced mixture of the particles throughout the carrier air. Have ing produced a mixture in which the para ticles are difiused equally throughout the H) carrier air it is possible, and maybe desirable, to divide the stream into two or more streams of equal or unequal size but'having the same proportions of particles and carrier m air. I use the term air in a generic sense to 1%: include atmosphericair or any other gase ous medium adapted for the particular 'purose.

p The invention is intended more particu- Nw larly for use in pulverized coal burning sys- 2'0 terns and will be described .in. connection therewith. 1 I v In the burning of pulverized'fuel, and particularly-in installations having two or more N, burners in one furnace, it is of importance that an equal supply of fuel be delivered to each burnen It has-been the practice to divide the total supply of fuel from a unit pulverizer or central bin in'to a'plurality of streams to supply individual burners, but till the difficulty has been to secure the distribution of the fuel in the carrier air so that substantially the same amount of fuel will at all times be contained in the several streams. It is the object of the present invention to provide .a method by which the fuel particles will be diffused uniformly throughout the carrier air and thereby the desired equality ofdistribution to each of the burners in the installation secured. This is accomplished withoutithe use of internal moving parts. j e In the accompanying-drawings Fig. 1 is a more ior less diagrammatic representation of a ipulverized fuel burning system ;.to illus- Etrate the relation of the distributor to the system"; and Figs. 2, 4, 6, 8 and 10 are vertical sections, partly in elevation'on the planes of V the lines indicated inZF-i-gs. 3, 5, 7, :9 and '11; p p .anrlthe latter figures are horizontal sections so on the planes of the correspondinglymarked 1928. :Serial No. 269,923.

lines of Figs.2, 4, 6, 8 and 10. These relate to separate embodiments of the invention.

Referring to Fig. 1, the letter A designates a bin containing the fuel to be pulverized; B a pulverizer of any suitable type Operated by a motor O The pulverized material is blown out by a fan inside the casing D, the

furnace of the boiler I. The air for Opera;-

tion of the distributor is supplied by any suitable pump K and conveyedto the distributor by thepipe 7. i 7

With thisdescription of the general layout in which the relation of the distributor in the system will be understood, I will describe several forms of the distributors which may be used, these being designated in Fig. 1, generally, by the letter F.

Referring to the remaining figures of the drawings, the 1111111811311 designates a portion'of the discharge line fromfthe pulverizer and through which the fuel, suspended in the carrier air, is conveyed. The Outlet end of this pipe may be enlarged. to provide a chamber 2 from which-pipes 3 lead'to individual burners. zAt some point along the length of pipe 1, and preferably in proximity to the distributing chamber 2 means are provi-ded for setting up sufficient turbulence in the strearnof fuel to bring aboutpa re-distribution of the particles of fuel suspended in the carrier air. This may be accomplished 99 egg by imparting a whirling motion to the stream, one means for so doing being described in the application for patent of E. Peabody, Serial No. 193,869 May 24th 1927,

which rotating blades are employed, Ac-

cording 7130 the present invention, however, the desired turbulence is effected by. inject- ,a small current of high pressure airinto the moving stream of coal and carrier air, before it reaches the branch fpipes. e

The current of air for this purpose may be introduced in any of the ways indicated in the drawings.

Referring first to Figs. 2 and 3, in the desired section of pipe 1 are formed a plurality of ducts 4 tangential to the inner wall of the pipe. These ducts lead from a chamber 5 the outer wall 6 of which completelyencloses the section of pipe 1 in which the izer or a central bin, the particles of fuel are not evenly or uniformly distributed through the carrier air. That is, the mixture will vary from rich to lean, as to fuel content, in any section of the stream.

Assuming that thestream through pipe 1 travels at the rate of approximately sixty (60) feet per second and that the air entering through pipe 7 is undera greater pressure than that of the carrier air, the stream of carrier air and fuel as itflovvs past the ducts 4, will be given a rapid whirling motion by the air jets escaping through the ducts. The creation of avortex in which the I stream has unequal angular velocities at different points. effects a movement .of the particles of fuel in a general direction transverseto the line 'oftravel of the stream. the breaking up of the richer portions and a more even distribution of the particles throughout the mass. I

.From pipe 1 the fuel enters chamber 2 from which it is distributed throughpipes 3 in as many streams as there are burners to be supplied, the individual streams being substantially uniformly balanced as to fuel content. l f

In devising a method for securing substantial uniformitvof fuel distribution in the carrier air it is necessary to'bear in mind that such air is traveling with its. load'of fuel through pipe let the rate of approximately 60 feet perlsecond, and that the mass after being given a whirling motion, is not retained in chamber 2 but flows therethrough and through the distributing pipes 3 at substantially the same rate. The problem presented is therefore different from that wherein .provision is made for giving the fuel a rapidwhirling motion as it enters the com 'bustion chamber for the purpose of effectan intimate mixture of the fuel and the air for combustion. The carrier airis generally from 10% to 50% of that" necessary for complete comhustion.-;-The secondary air, or that for complete combustion, is introduced into the furnace through a register as described in Patent No. 1,738,176, granted December 3, 1929 for fuel burners.

The present invention is solely for the treatment of the fuel on its way to the burners and is not concerned with the means employed for burning the fuel or for admit-ting air for combustion thereto.

A modified arrangement is shown in Figs. 4 and 5 in which the pipe 1 is formed with an. enlarged section 8 in proximity to the cha ns ber 2. The airvis injected through two 1n-- lets 9 tangential to the innerwall of section 8. The action of the air currents upon the fuelstream is substantially the same as that described with reference to Figs. 2 and 3.

Instead of injecting the air jets in a plane normal to the direction of travel of the fuel stream they maybe projected'at an angle thereto by the arrangement shown in Figs. 1 6 and 7. In this, the air is admitted through ably' formed so that their axes are tangential to the inner wall of pipe 1.

In the foregoing description it 'Wlll be notedthat the vortex effect is produced by jets of air under pressure being injected into the fuel stream from a source outside thereof and surrounding the stream so that the direct action of the air is on the periphery of the mass. This is of advantage in thatthe air jets penetrate the rapidly moving stream of fuel'and thus act not only upon its periphery but toward the center thereof, resulting in a more eifective diffusion of the fuel particles through the mass.

Some ofthe advantages attained by the above described'means are secured by the use of an air spray nozzle 13 mounted upon the end of a supply pipe 14, as shown in Figs. 8 and 9. The nozzle 13 maybe of any suitableform and is perforated as shown, to permit the escape of the air in a plurality of fine jets into the center of the stream of fuel.

As in Figs. 2 to 7, the fuel stream after being acted upon by the jets of air from the While the chamber 2 is shownin the several figures-as an enlargement of the pipe 1', or as practically acontinuation of said pipe, it is not essential to the invention that the exactform or relation of these parts be as shown, for, as before stated, the drawings are more or less diagrammatic and are not intended as exact representations of the form or arrangement which may be used in practice. The drawings, however, serve to illustrate the principle of the invention and the mode in which it is to be applied.

What I claim is:

1. A system comprising a source of pulverized material suspended in carrier air, a conduit leading therefrom, a plurality of branch conduits, a distributor connecting the main conduit with the branch conduits, said distributor including means for injecting a current of air into a stream of the material flowing therethrough to effect a substantially uniform diffusion of the material through the carrier air.

2. A system comprising a device for pulverizing material, a main line for conveying said material suspended in carrier air, a distributor to which the main linesis connected, branch lines connected to said distributor, and means in said distributor for injecting a current of air into the moving stream of fuel and carrier air to efi'ect a substantially uniform diffusion of the material in the carrier air. v

3. A system comprising a source of pulverized fuel suspended in carrier air, a conduit leading therefrom, a plurality of branch conduits, a distributor connecting the main conduit and the branch conduits, said distributor including means for injecting a current of air tangentially into a stream of the material flowing therethrough to effect a substantially uniform diffusion of the fuel in ,the carrier air.

4. A system comprising a source of pulverized fuel suspended in carrier air, a. conduit leading therefrom, a plurality of branch conduits, a distributor connecting the main conduit and the branch conduits, said distributor including means for injecting into the moving stream a current of air substantially normal to the path of travel of said stream to effect therein a substantially uniform diffusion of the fuel in the carrier air.

Signed at New York in the county of New York and State of New York this 11th day of April, A. D. 1928.

HORACE T. DYER. 

